using System;
using System.IO;
using System.Collections.Generic;

namespace PickGold.Zip
{

	partial class ZipFile
	{
		/// <summary>
		///   Adds to the ZipFile a set of files from the current working directory on
		///   disk, that conform to the specified criteria.
		/// </summary>
		///
		/// <remarks>
		/// <para>
		///   This method selects files from the the current working directory matching
		///   the specified criteria, and adds them to the ZipFile.
		/// </para>
		///
		/// <para>
		///   Specify the criteria in statements of 3 elements: a noun, an operator, and
		///   a value.  Consider the string "name != *.doc" .  The noun is "name".  The
		///   operator is "!=", implying "Not Equal".  The value is "*.doc".  That
		///   criterion, in English, says "all files with a name that does not end in
		///   the .doc extension."
		/// </para>
		///
		/// <para>
		///   Supported nouns include "name" (or "filename") for the filename; "atime",
		///   "mtime", and "ctime" for last access time, last modfied time, and created
		///   time of the file, respectively; "attributes" (or "attrs") for the file
		///   attributes; "size" (or "length") for the file length (uncompressed), and
		///   "type" for the type of object, either a file or a directory.  The
		///   "attributes", "name" and "type" nouns both support = and != as operators.
		///   The "size", "atime", "mtime", and "ctime" nouns support = and !=, and
		///   &gt;, &gt;=, &lt;, &lt;= as well. The times are taken to be expressed in
		///   local time.
		/// </para>
		///
		/// <para>
		/// Specify values for the file attributes as a string with one or more of the
		/// characters H,R,S,A,I,L in any order, implying file attributes of Hidden,
		/// ReadOnly, System, Archive, NotContextIndexed, and ReparsePoint (symbolic
		/// link) respectively.
		/// </para>
		///
		/// <para>
		/// To specify a time, use YYYY-MM-DD-HH:mm:ss or YYYY/MM/DD-HH:mm:ss as the
		/// format.  If you omit the HH:mm:ss portion, it is assumed to be 00:00:00
		/// (midnight).
		/// </para>
		///
		/// <para>
		/// The value for a size criterion is expressed in integer quantities of bytes,
		/// kilobytes (use k or kb after the number), megabytes (m or mb), or gigabytes
		/// (g or gb).
		/// </para>
		///
		/// <para>
		/// The value for a name is a pattern to match against the filename, potentially
		/// including wildcards.  The pattern follows CMD.exe glob rules: * implies one
		/// or more of any character, while ?  implies one character.  If the name
		/// pattern contains any slashes, it is matched to the entire filename,
		/// including the path; otherwise, it is matched against only the filename
		/// without the path.  This means a pattern of "*\*.*" matches all files one
		/// directory level deep, while a pattern of "*.*" matches all files in all
		/// directories.
		/// </para>
		///
		/// <para>
		/// To specify a name pattern that includes spaces, use single quotes around the
		/// pattern.  A pattern of "'* *.*'" will match all files that have spaces in
		/// the filename.  The full criteria string for that would be "name = '* *.*'" .
		/// </para>
		///
		/// <para>
		/// The value for a type criterion is either F (implying a file) or D (implying
		/// a directory).
		/// </para>
		///
		/// <para>
		/// Some examples:
		/// </para>
		///
		/// <list type="table">
		///   <listheader>
		///     <term>criteria</term>
		///     <description>Files retrieved</description>
		///   </listheader>
		///
		///   <item>
		///     <term>name != *.xls </term>
		///     <description>any file with an extension that is not .xls
		///     </description>
		///   </item>
		///
		///   <item>
		///     <term>name = *.mp3 </term>
		///     <description>any file with a .mp3 extension.
		///     </description>
		///   </item>
		///
		///   <item>
		///     <term>*.mp3</term>
		///     <description>(same as above) any file with a .mp3 extension.
		///     </description>
		///   </item>
		///
		///   <item>
		///     <term>attributes = A </term>
		///     <description>all files whose attributes include the Archive bit.
		///     </description>
		///   </item>
		///
		///   <item>
		///     <term>attributes != H </term>
		///     <description>all files whose attributes do not include the Hidden bit.
		///     </description>
		///   </item>
		///
		///   <item>
		///     <term>mtime > 2009-01-01</term>
		///     <description>all files with a last modified time after January 1st, 2009.
		///     </description>
		///   </item>
		///
		///   <item>
		///     <term>size > 2gb</term>
		///     <description>all files whose uncompressed size is greater than 2gb.
		///     </description>
		///   </item>
		///
		///   <item>
		///     <term>type = D</term>
		///     <description>all directories in the filesystem. </description>
		///   </item>
		///
		/// </list>
		///
		/// <para>
		/// You can combine criteria with the conjunctions AND or OR. Using a string
		/// like "name = *.txt AND size &gt;= 100k" for the selectionCriteria retrieves
		/// entries whose names end in .txt, and whose uncompressed size is greater than
		/// or equal to 100 kilobytes.
		/// </para>
		///
		/// <para>
		/// For more complex combinations of criteria, you can use parenthesis to group
		/// clauses in the boolean logic.  Without parenthesis, the precedence of the
		/// criterion atoms is determined by order of appearance.  Unlike the C#
		/// language, the AND conjunction does not take precendence over the logical OR.
		/// This is important only in strings that contain 3 or more criterion atoms.
		/// In other words, "name = *.txt and size &gt; 1000 or attributes = H" implies
		/// "((name = *.txt AND size &gt; 1000) OR attributes = H)" while "attributes =
		/// H OR name = *.txt and size &gt; 1000" evaluates to "((attributes = H OR name
		/// = *.txt) AND size &gt; 1000)".  When in doubt, use parenthesis.
		/// </para>
		///
		/// <para>
		/// Using time properties requires some extra care. If you want to retrieve all
		/// entries that were last updated on 2009 February 14, specify a time range
		/// like so:"mtime &gt;= 2009-02-14 AND mtime &lt; 2009-02-15".  Read this to
		/// say: all files updated after 12:00am on February 14th, until 12:00am on
		/// February 15th.  You can use the same bracketing approach to specify any time
		/// period - a year, a month, a week, and so on.
		/// </para>
		///
		/// <para>
		/// The syntax allows one special case: if you provide a string with no spaces, it is
		/// treated as a pattern to match for the filename.  Therefore a string like "*.xls"
		/// will be equivalent to specifying "name = *.xls".
		/// </para>
		///
		/// <para>
		/// There is no logic in this method that insures that the file inclusion
		/// criteria are internally consistent.  For example, it's possible to specify
		/// criteria that says the file must have a size of less than 100 bytes, as well
		/// as a size that is greater than 1000 bytes. Obviously no file will ever
		/// satisfy such criteria, but this method does not detect such logical
		/// inconsistencies. The caller is responsible for insuring the criteria are
		/// sensible.
		/// </para>
		///
		/// <para>
		///   Using this method, the file selection does not recurse into
		///   subdirectories, and the full path of the selected files is included in the
		///   entries added into the zip archive.  If you don't like these behaviors,
		///   see the other overloads of this method.
		/// </para>
		/// </remarks>
		///
		/// <example>
		/// This example zips up all *.csv files in the current working directory.
		/// <code>
		/// using (ZipFile zip = new ZipFile())
		/// {
		///     // To just match on filename wildcards,
		///     // use the shorthand form of the selectionCriteria string.
		///     zip.AddSelectedFiles("*.csv");
		///     zip.Save(PathToZipArchive);
		/// }
		/// </code>
		/// <code lang="VB">
		/// Using zip As ZipFile = New ZipFile()
		///     zip.AddSelectedFiles("*.csv")
		///     zip.Save(PathToZipArchive)
		/// End Using
		/// </code>
		/// </example>
		///
		/// <param name="selectionCriteria">The criteria for file selection</param>
		public void AddSelectedFiles(String selectionCriteria)
		{
			this.AddSelectedFiles(selectionCriteria, ".", null, false);
		}

		/// <summary>
		///   Adds to the ZipFile a set of files from the disk that conform to the
		///   specified criteria, optionally recursing into subdirectories.
		/// </summary>
		///
		/// <remarks>
		/// <para>
		///   This method selects files from the the current working directory matching
		///   the specified criteria, and adds them to the ZipFile.  If
		///   <c>recurseDirectories</c> is true, files are also selected from
		///   subdirectories, and the directory structure in the filesystem is
		///   reproduced in the zip archive, rooted at the current working directory.
		/// </para>
		///
		/// <para>
		///   Using this method, the full path of the selected files is included in the
		///   entries added into the zip archive.  If you don't want this behavior, use
		///   one of the overloads of this method that allows the specification of a
		///   <c>directoryInArchive</c>.
		/// </para>
		///
		/// <para>
		///   For details on the syntax for the selectionCriteria parameter, see <see
		///   cref="AddSelectedFiles(String)"/>.
		/// </para>
		///
		/// </remarks>
		///
		/// <example>
		///
		///   This example zips up all *.xml files in the current working directory, or any
		///   subdirectory, that are larger than 1mb.
		///
		/// <code>
		/// using (ZipFile zip = new ZipFile())
		/// {
		///     // Use a compound expression in the selectionCriteria string.
		///     zip.AddSelectedFiles("name = *.xml  and  size > 1024kb", true);
		///     zip.Save(PathToZipArchive);
		/// }
		/// </code>
		/// <code lang="VB">
		/// Using zip As ZipFile = New ZipFile()
		///     ' Use a compound expression in the selectionCriteria string.
		///     zip.AddSelectedFiles("name = *.xml  and  size > 1024kb", true)
		///     zip.Save(PathToZipArchive)
		/// End Using
		/// </code>
		/// </example>
		///
		/// <param name="selectionCriteria">The criteria for file selection</param>
		///
		/// <param name="recurseDirectories">
		///   If true, the file selection will recurse into subdirectories.
		/// </param>
		public void AddSelectedFiles(String selectionCriteria, bool recurseDirectories)
		{
			this.AddSelectedFiles(selectionCriteria, ".", null, recurseDirectories);
		}

		/// <summary>
		///   Adds to the ZipFile a set of files from a specified directory in the
		///   filesystem, that conform to the specified criteria.
		/// </summary>
		///
		/// <remarks>
		/// <para>
		///   This method selects files that conform to the specified criteria, from the
		///   the specified directory on disk, and adds them to the ZipFile.  The search
		///   does not recurse into subdirectores.
		/// </para>
		///
		/// <para>
		///   Using this method, the full filesystem path of the files on disk is
		///   reproduced on the entries added to the zip file.  If you don't want this
		///   behavior, use one of the other overloads of this method.
		/// </para>
		///
		/// <para>
		///   For details on the syntax for the selectionCriteria parameter, see <see
		///   cref="AddSelectedFiles(String)"/>.
		/// </para>
		///
		/// </remarks>
		///
		/// <example>
		///
		///   This example zips up all *.xml files larger than 1mb in the directory
		///   given by "d:\rawdata".
		///
		/// <code>
		/// using (ZipFile zip = new ZipFile())
		/// {
		///     // Use a compound expression in the selectionCriteria string.
		///     zip.AddSelectedFiles("name = *.xml  and  size > 1024kb", "d:\\rawdata");
		///     zip.Save(PathToZipArchive);
		/// }
		/// </code>
		///
		/// <code lang="VB">
		/// Using zip As ZipFile = New ZipFile()
		///     ' Use a compound expression in the selectionCriteria string.
		///     zip.AddSelectedFiles("name = *.xml  and  size > 1024kb", "d:\rawdata)
		///     zip.Save(PathToZipArchive)
		/// End Using
		/// </code>
		/// </example>
		///
		/// <param name="selectionCriteria">The criteria for file selection</param>
		///
		/// <param name="directoryOnDisk">
		/// The name of the directory on the disk from which to select files.
		/// </param>
		public void AddSelectedFiles(String selectionCriteria, String directoryOnDisk)
		{
			this.AddSelectedFiles(selectionCriteria, directoryOnDisk, null, false);
		}


		/// <summary>
		///   Adds to the ZipFile a set of files from the specified directory on disk,
		///   that conform to the specified criteria.
		/// </summary>
		///
		/// <remarks>
		///
		/// <para>
		///   This method selects files from the the specified disk directory matching
		///   the specified selection criteria, and adds them to the ZipFile.  If
		///   <c>recurseDirectories</c> is true, files are also selected from
		///   subdirectories.
		/// </para>
		///
		/// <para>
		///   The full directory structure in the filesystem is reproduced on the
		///   entries added to the zip archive.  If you don't want this behavior, use
		///   one of the overloads of this method that allows the specification of a
		///   <c>directoryInArchive</c>.
		/// </para>
		///
		/// <para>
		///   For details on the syntax for the selectionCriteria parameter, see <see
		///   cref="AddSelectedFiles(String)"/>.
		/// </para>
		/// </remarks>
		///
		/// <example>
		///
		///   This example zips up all *.csv files in the "files" directory, or any
		///   subdirectory, that have been saved since 2009 February 14th.
		///
		/// <code>
		/// using (ZipFile zip = new ZipFile())
		/// {
		///     // Use a compound expression in the selectionCriteria string.
		///     zip.AddSelectedFiles("name = *.csv  and  mtime > 2009-02-14", "files", true);
		///     zip.Save(PathToZipArchive);
		/// }
		/// </code>
		/// <code lang="VB">
		/// Using zip As ZipFile = New ZipFile()
		///     ' Use a compound expression in the selectionCriteria string.
		///     zip.AddSelectedFiles("name = *.csv  and  mtime > 2009-02-14", "files", true)
		///     zip.Save(PathToZipArchive)
		/// End Using
		/// </code>
		/// </example>
		///
		/// <example>
		///   This example zips up all files in the current working
		///   directory, and all its child directories, except those in
		///   the <c>excludethis</c> subdirectory.
		/// <code lang="VB">
		/// Using Zip As ZipFile = New ZipFile(zipfile)
		///   Zip.AddSelectedFfiles("name != 'excludethis\*.*'", datapath, True)
		///   Zip.Save()
		/// End Using
		/// </code>
		/// </example>
		///
		/// <param name="selectionCriteria">The criteria for file selection</param>
		///
		/// <param name="directoryOnDisk">
		///   The filesystem path from which to select files.
		/// </param>
		///
		/// <param name="recurseDirectories">
		///   If true, the file selection will recurse into subdirectories.
		/// </param>
		public void AddSelectedFiles(String selectionCriteria, String directoryOnDisk, bool recurseDirectories)
		{
			this.AddSelectedFiles(selectionCriteria, directoryOnDisk, null, recurseDirectories);
		}


		/// <summary>
		///   Adds to the ZipFile a selection of files from the specified directory on
		///   disk, that conform to the specified criteria, and using a specified root
		///   path for entries added to the zip archive.
		/// </summary>
		///
		/// <remarks>
		/// <para>
		///   This method selects files from the specified disk directory matching the
		///   specified selection criteria, and adds those files to the ZipFile, using
		///   the specified directory path in the archive.  The search does not recurse
		///   into subdirectories.  For details on the syntax for the selectionCriteria
		///   parameter, see <see cref="AddSelectedFiles(String)" />.
		/// </para>
		///
		/// </remarks>
		///
		/// <example>
		///
		///   This example zips up all *.psd files in the "photos" directory that have
		///   been saved since 2009 February 14th, and puts them all in a zip file,
		///   using the directory name of "content" in the zip archive itself. When the
		///   zip archive is unzipped, the folder containing the .psd files will be
		///   named "content".
		///
		/// <code>
		/// using (ZipFile zip = new ZipFile())
		/// {
		///     // Use a compound expression in the selectionCriteria string.
		///     zip.AddSelectedFiles("name = *.psd  and  mtime > 2009-02-14", "photos", "content");
		///     zip.Save(PathToZipArchive);
		/// }
		/// </code>
		/// <code lang="VB">
		/// Using zip As ZipFile = New ZipFile
		///     zip.AddSelectedFiles("name = *.psd  and  mtime > 2009-02-14", "photos", "content")
		///     zip.Save(PathToZipArchive)
		/// End Using
		/// </code>
		/// </example>
		///
		/// <param name="selectionCriteria">
		///   The criteria for selection of files to add to the <c>ZipFile</c>.
		/// </param>
		///
		/// <param name="directoryOnDisk">
		///   The path to the directory in the filesystem from which to select files.
		/// </param>
		///
		/// <param name="directoryPathInArchive">
		///   Specifies a directory path to use to in place of the
		///   <c>directoryOnDisk</c>.  This path may, or may not, correspond to a real
		///   directory in the current filesystem.  If the files within the zip are
		///   later extracted, this is the path used for the extracted file.  Passing
		///   null (nothing in VB) will use the path on the file name, if any; in other
		///   words it would use <c>directoryOnDisk</c>, plus any subdirectory.  Passing
		///   the empty string ("") will insert the item at the root path within the
		///   archive.
		/// </param>
		public void AddSelectedFiles(String selectionCriteria,
									 String directoryOnDisk,
									 String directoryPathInArchive)
		{
			this.AddSelectedFiles(selectionCriteria, directoryOnDisk, directoryPathInArchive, false);
		}

		/// <summary>
		///   Adds to the ZipFile a selection of files from the specified directory on
		///   disk, that conform to the specified criteria, optionally recursing through
		///   subdirectories, and using a specified root path for entries added to the
		///   zip archive.
		/// </summary>
		///
		/// <remarks>
		///   This method selects files from the specified disk directory that match the
		///   specified selection criteria, and adds those files to the ZipFile, using
		///   the specified directory path in the archive. If <c>recurseDirectories</c>
		///   is true, files are also selected from subdirectories, and the directory
		///   structure in the filesystem is reproduced in the zip archive, rooted at
		///   the directory specified by <c>directoryOnDisk</c>.  For details on the
		///   syntax for the selectionCriteria parameter, see <see
		///   cref="AddSelectedFiles(String)" />.
		/// </remarks>
		///
		/// <example>
		///
		///   This example zips up all files that are NOT *.pst files, in the current
		///   working directory and any subdirectories.
		///
		/// <code>
		/// using (ZipFile zip = new ZipFile())
		/// {
		///     zip.AddSelectedFiles("name != *.pst", SourceDirectory, "backup", true);
		///     zip.Save(PathToZipArchive);
		/// }
		/// </code>
		/// <code lang="VB">
		/// Using zip As ZipFile = New ZipFile
		///     zip.AddSelectedFiles("name != *.pst", SourceDirectory, "backup", true)
		///     zip.Save(PathToZipArchive)
		/// End Using
		/// </code>
		/// </example>
		///
		/// <param name="selectionCriteria">
		///   The criteria for selection of files to add to the <c>ZipFile</c>.
		/// </param>
		///
		/// <param name="directoryOnDisk">
		///   The path to the directory in the filesystem from which to select files.
		/// </param>
		///
		/// <param name="directoryPathInArchive">
		///   Specifies a directory path to use to in place of the
		///   <c>directoryOnDisk</c>.  This path may, or may not, correspond to a real
		///   directory in the current filesystem.  If the files within the zip are
		///   later extracted, this is the path used for the extracted file.  Passing
		///   null (nothing in VB) will use the path on the file name, if any; in other
		///   words it would use <c>directoryOnDisk</c>, plus any subdirectory.  Passing
		///   the empty string ("") will insert the item at the root path within the
		///   archive.
		/// </param>
		///
		/// <param name="recurseDirectories">
		///   If true, the method also scans subdirectories for files matching the
		///   criteria.
		/// </param>
		public void AddSelectedFiles(String selectionCriteria,
									 String directoryOnDisk,
									 String directoryPathInArchive,
									 bool recurseDirectories)
		{
			_AddOrUpdateSelectedFiles(selectionCriteria,
									  directoryOnDisk,
									  directoryPathInArchive,
									  recurseDirectories,
									  false);
		}

		/// <summary>
		///   Updates the ZipFile with a selection of files from the disk that conform
		///   to the specified criteria.
		/// </summary>
		///
		/// <remarks>
		///   This method selects files from the specified disk directory that match the
		///   specified selection criteria, and Updates the <c>ZipFile</c> with those
		///   files, using the specified directory path in the archive. If
		///   <c>recurseDirectories</c> is true, files are also selected from
		///   subdirectories, and the directory structure in the filesystem is
		///   reproduced in the zip archive, rooted at the directory specified by
		///   <c>directoryOnDisk</c>.  For details on the syntax for the
		///   selectionCriteria parameter, see <see cref="AddSelectedFiles(String)" />.
		/// </remarks>
		///
		/// <param name="selectionCriteria">
		///   The criteria for selection of files to add to the <c>ZipFile</c>.
		/// </param>
		///
		/// <param name="directoryOnDisk">
		///   The path to the directory in the filesystem from which to select files.
		/// </param>
		///
		/// <param name="directoryPathInArchive">
		///   Specifies a directory path to use to in place of the
		///   <c>directoryOnDisk</c>. This path may, or may not, correspond to a
		///   real directory in the current filesystem. If the files within the zip
		///   are later extracted, this is the path used for the extracted file.
		///   Passing null (nothing in VB) will use the path on the file name, if
		///   any; in other words it would use <c>directoryOnDisk</c>, plus any
		///   subdirectory.  Passing the empty string ("") will insert the item at
		///   the root path within the archive.
		/// </param>
		///
		/// <param name="recurseDirectories">
		///   If true, the method also scans subdirectories for files matching the criteria.
		/// </param>
		///
		/// <seealso cref="AddSelectedFiles(String, String, String, bool)" />
		public void UpdateSelectedFiles(String selectionCriteria,
									 String directoryOnDisk,
									 String directoryPathInArchive,
									 bool recurseDirectories)
		{
			_AddOrUpdateSelectedFiles(selectionCriteria,
									  directoryOnDisk,
									  directoryPathInArchive,
									  recurseDirectories,
									  true);
		}


		private string EnsureendInSlash(string s)
		{
			if (s.EndsWith("\\")) return s;
			return s + "\\";
		}

		private void _AddOrUpdateSelectedFiles(String selectionCriteria,
											   String directoryOnDisk,
											   String directoryPathInArchive,
											   bool recurseDirectories,
											   bool wantUpdate)
		{
			if (directoryOnDisk == null && (Directory.Exists(selectionCriteria)))
			{
				directoryOnDisk = selectionCriteria;
				selectionCriteria = "*.*";
			}
			else if (String.IsNullOrEmpty(directoryOnDisk))
			{
				directoryOnDisk = ".";
			}

			// workitem 9176
			while (directoryOnDisk.EndsWith("\\")) directoryOnDisk = directoryOnDisk.Substring(0, directoryOnDisk.Length - 1);
			if (Verbose) StatusMessageTextWriter.WriteLine("adding selection '{0}' from dir '{1}'...",
															   selectionCriteria, directoryOnDisk);
			var ff = new FileSelector(selectionCriteria, AddDirectoryWillTraverseReparsePoints);
			var itemsToAdd = ff.SelectFiles(directoryOnDisk, recurseDirectories);

			if (Verbose) StatusMessageTextWriter.WriteLine("found {0} files...", itemsToAdd.Count);

			OnAddStarted();

			AddOrUpdateAction action = (wantUpdate) ? AddOrUpdateAction.AddOrUpdate : AddOrUpdateAction.AddOnly;
			foreach (var item in itemsToAdd)
			{
				// workitem 10153
				string dirInArchive = (directoryPathInArchive == null)
					? null
					// workitem 12260
					: ReplaceLeadingDirectory(Path.GetDirectoryName(item),
											  directoryOnDisk,
											  directoryPathInArchive);

				if (File.Exists(item))
				{
					if (wantUpdate)
						this.UpdateFile(item, dirInArchive);
					else
						this.AddFile(item, dirInArchive);
				}
				else
				{
					// this adds "just" the directory, without recursing to the contained files
					AddOrUpdateDirectoryImpl(item, dirInArchive, action, false, 0);
				}
			}

			OnAddCompleted();
		}


		// workitem 12260
		private static string ReplaceLeadingDirectory(string original,
													  string pattern,
													  string replacement)
		{
			string upperString = original.ToUpper();
			string upperPattern = pattern.ToUpper();
			int p1 = upperString.IndexOf(upperPattern);
			if (p1 != 0) return original;
			return replacement + original.Substring(upperPattern.Length);
		}

#if NOT
        private static string ReplaceEx(string original,
                                                      string pattern,
                                                      string replacement)
        {
            int count, position0, position1;
            count = position0 = position1 = 0;
            string upperString = original.ToUpper();
            string upperPattern = pattern.ToUpper();
            int inc = (original.Length/pattern.Length) *
                (replacement.Length-pattern.Length);
            char [] chars = new char[original.Length + Math.Max(0, inc)];
            while( (position1 = upperString.IndexOf(upperPattern,
                                                    position0)) != -1 )
            {
                for ( int i=position0 ; i < position1 ; ++i )
                    chars[count++] = original[i];
                for ( int i=0 ; i < replacement.Length ; ++i )
                    chars[count++] = replacement[i];
                position0 = position1+pattern.Length;
            }
            if ( position0 == 0 ) return original;
            for ( int i=position0 ; i < original.Length ; ++i )
                chars[count++] = original[i];
            return new string(chars, 0, count);
        }
#endif

		/// <summary>
		/// Retrieve entries from the zipfile by specified criteria.
		/// </summary>
		///
		/// <remarks>
		/// <para>
		/// This method allows callers to retrieve the collection of entries from the zipfile
		/// that fit the specified criteria.  The criteria are described in a string format, and
		/// can include patterns for the filename; constraints on the size of the entry;
		/// constraints on the last modified, created, or last accessed time for the file
		/// described by the entry; or the attributes of the entry.
		/// </para>
		///
		/// <para>
		/// For details on the syntax for the selectionCriteria parameter, see <see
		/// cref="AddSelectedFiles(String)"/>.
		/// </para>
		///
		/// <para>
		/// This method is intended for use with a ZipFile that has been read from storage.
		/// When creating a new ZipFile, this method will work only after the ZipArchive has
		/// been Saved to the disk (the ZipFile class subsequently and implicitly reads the Zip
		/// archive from storage.)  Calling SelectEntries on a ZipFile that has not yet been
		/// saved will deliver undefined results.
		/// </para>
		/// </remarks>
		///
		/// <exception cref="System.Exception">
		/// Thrown if selectionCriteria has an invalid syntax.
		/// </exception>
		///
		/// <example>
		/// This example selects all the PhotoShop files from within an archive, and extracts them
		/// to the current working directory.
		/// <code>
		/// using (ZipFile zip1 = ZipFile.Read(ZipFileName))
		/// {
		///     var PhotoShopFiles = zip1.SelectEntries("*.psd");
		///     foreach (ZipEntry psd in PhotoShopFiles)
		///     {
		///         psd.Extract();
		///     }
		/// }
		/// </code>
		/// <code lang="VB">
		/// Using zip1 As ZipFile = ZipFile.Read(ZipFileName)
		///     Dim PhotoShopFiles as ICollection(Of ZipEntry)
		///     PhotoShopFiles = zip1.SelectEntries("*.psd")
		///     Dim psd As ZipEntry
		///     For Each psd In PhotoShopFiles
		///         psd.Extract
		///     Next
		/// End Using
		/// </code>
		/// </example>
		/// <param name="selectionCriteria">the string that specifies which entries to select</param>
		/// <returns>a collection of ZipEntry objects that conform to the inclusion spec</returns>
		public ICollection<ZipEntry> SelectEntries(String selectionCriteria)
		{
			var ff = new FileSelector(selectionCriteria, AddDirectoryWillTraverseReparsePoints);
			return ff.SelectEntries(this);
		}


		/// <summary>
		/// Retrieve entries from the zipfile by specified criteria.
		/// </summary>
		///
		/// <remarks>
		/// <para>
		/// This method allows callers to retrieve the collection of entries from the zipfile
		/// that fit the specified criteria.  The criteria are described in a string format, and
		/// can include patterns for the filename; constraints on the size of the entry;
		/// constraints on the last modified, created, or last accessed time for the file
		/// described by the entry; or the attributes of the entry.
		/// </para>
		///
		/// <para>
		/// For details on the syntax for the selectionCriteria parameter, see <see
		/// cref="AddSelectedFiles(String)"/>.
		/// </para>
		///
		/// <para>
		/// This method is intended for use with a ZipFile that has been read from storage.
		/// When creating a new ZipFile, this method will work only after the ZipArchive has
		/// been Saved to the disk (the ZipFile class subsequently and implicitly reads the Zip
		/// archive from storage.)  Calling SelectEntries on a ZipFile that has not yet been
		/// saved will deliver undefined results.
		/// </para>
		/// </remarks>
		///
		/// <exception cref="System.Exception">
		/// Thrown if selectionCriteria has an invalid syntax.
		/// </exception>
		///
		/// <example>
		/// <code>
		/// using (ZipFile zip1 = ZipFile.Read(ZipFileName))
		/// {
		///     var UpdatedPhotoShopFiles = zip1.SelectEntries("*.psd", "UpdatedFiles");
		///     foreach (ZipEntry e in UpdatedPhotoShopFiles)
		///     {
		///         // prompt for extract here
		///         if (WantExtract(e.FileName))
		///             e.Extract();
		///     }
		/// }
		/// </code>
		/// <code lang="VB">
		/// Using zip1 As ZipFile = ZipFile.Read(ZipFileName)
		///     Dim UpdatedPhotoShopFiles As ICollection(Of ZipEntry) = zip1.SelectEntries("*.psd", "UpdatedFiles")
		///     Dim e As ZipEntry
		///     For Each e In UpdatedPhotoShopFiles
		///         ' prompt for extract here
		///         If Me.WantExtract(e.FileName) Then
		///             e.Extract
		///         End If
		///     Next
		/// End Using
		/// </code>
		/// </example>
		/// <param name="selectionCriteria">the string that specifies which entries to select</param>
		///
		/// <param name="directoryPathInArchive">
		/// the directory in the archive from which to select entries. If null, then
		/// all directories in the archive are used.
		/// </param>
		///
		/// <returns>a collection of ZipEntry objects that conform to the inclusion spec</returns>
		public ICollection<ZipEntry> SelectEntries(String selectionCriteria, string directoryPathInArchive)
		{
			var ff = new FileSelector(selectionCriteria, AddDirectoryWillTraverseReparsePoints);
			return ff.SelectEntries(this, directoryPathInArchive);
		}



		/// <summary>
		/// Remove entries from the zipfile by specified criteria.
		/// </summary>
		///
		/// <remarks>
		/// <para>
		/// This method allows callers to remove the collection of entries from the zipfile
		/// that fit the specified criteria.  The criteria are described in a string format, and
		/// can include patterns for the filename; constraints on the size of the entry;
		/// constraints on the last modified, created, or last accessed time for the file
		/// described by the entry; or the attributes of the entry.
		/// </para>
		///
		/// <para>
		/// For details on the syntax for the selectionCriteria parameter, see <see
		/// cref="AddSelectedFiles(String)"/>.
		/// </para>
		///
		/// <para>
		/// This method is intended for use with a ZipFile that has been read from storage.
		/// When creating a new ZipFile, this method will work only after the ZipArchive has
		/// been Saved to the disk (the ZipFile class subsequently and implicitly reads the Zip
		/// archive from storage.)  Calling SelectEntries on a ZipFile that has not yet been
		/// saved will deliver undefined results.
		/// </para>
		/// </remarks>
		///
		/// <exception cref="System.Exception">
		/// Thrown if selectionCriteria has an invalid syntax.
		/// </exception>
		///
		/// <example>
		/// This example removes all entries in a zip file that were modified prior to January 1st, 2008.
		/// <code>
		/// using (ZipFile zip1 = ZipFile.Read(ZipFileName))
		/// {
		///     // remove all entries from prior to Jan 1, 2008
		///     zip1.RemoveEntries("mtime &lt; 2008-01-01");
		///     // don't forget to save the archive!
		///     zip1.Save();
		/// }
		/// </code>
		/// <code lang="VB">
		/// Using zip As ZipFile = ZipFile.Read(ZipFileName)
		///     ' remove all entries from prior to Jan 1, 2008
		///     zip1.RemoveEntries("mtime &lt; 2008-01-01")
		///     ' do not forget to save the archive!
		///     zip1.Save
		/// End Using
		/// </code>
		/// </example>
		/// <param name="selectionCriteria">the string that specifies which entries to select</param>
		/// <returns>the number of entries removed</returns>
		public int RemoveSelectedEntries(String selectionCriteria)
		{
			var selection = this.SelectEntries(selectionCriteria);
			this.RemoveEntries(selection);
			return selection.Count;
		}


		/// <summary>
		/// Remove entries from the zipfile by specified criteria, and within the specified
		/// path in the archive.
		/// </summary>
		///
		/// <remarks>
		/// <para>
		/// This method allows callers to remove the collection of entries from the zipfile
		/// that fit the specified criteria.  The criteria are described in a string format, and
		/// can include patterns for the filename; constraints on the size of the entry;
		/// constraints on the last modified, created, or last accessed time for the file
		/// described by the entry; or the attributes of the entry.
		/// </para>
		///
		/// <para>
		/// For details on the syntax for the selectionCriteria parameter, see <see
		/// cref="AddSelectedFiles(String)"/>.
		/// </para>
		///
		/// <para>
		/// This method is intended for use with a ZipFile that has been read from storage.
		/// When creating a new ZipFile, this method will work only after the ZipArchive has
		/// been Saved to the disk (the ZipFile class subsequently and implicitly reads the Zip
		/// archive from storage.)  Calling SelectEntries on a ZipFile that has not yet been
		/// saved will deliver undefined results.
		/// </para>
		/// </remarks>
		///
		/// <exception cref="System.Exception">
		/// Thrown if selectionCriteria has an invalid syntax.
		/// </exception>
		///
		/// <example>
		/// <code>
		/// using (ZipFile zip1 = ZipFile.Read(ZipFileName))
		/// {
		///     // remove all entries from prior to Jan 1, 2008
		///     zip1.RemoveEntries("mtime &lt; 2008-01-01", "documents");
		///     // a call to ZipFile.Save will make the modifications permanent
		///     zip1.Save();
		/// }
		/// </code>
		/// <code lang="VB">
		/// Using zip As ZipFile = ZipFile.Read(ZipFileName)
		///     ' remove all entries from prior to Jan 1, 2008
		///     zip1.RemoveEntries("mtime &lt; 2008-01-01", "documents")
		///     ' a call to ZipFile.Save will make the modifications permanent
		///     zip1.Save
		/// End Using
		/// </code>
		/// </example>
		///
		/// <param name="selectionCriteria">the string that specifies which entries to select</param>
		/// <param name="directoryPathInArchive">
		/// the directory in the archive from which to select entries. If null, then
		/// all directories in the archive are used.
		/// </param>
		/// <returns>the number of entries removed</returns>
		public int RemoveSelectedEntries(String selectionCriteria, string directoryPathInArchive)
		{
			var selection = this.SelectEntries(selectionCriteria, directoryPathInArchive);
			this.RemoveEntries(selection);
			return selection.Count;
		}


		/// <summary>
		/// Selects and Extracts a set of Entries from the ZipFile.
		/// </summary>
		///
		/// <remarks>
		/// <para>
		/// The entries are extracted into the current working directory.
		/// </para>
		///
		/// <para>
		/// If any of the files to be extracted already exist, then the action taken is as
		/// specified in the <see cref="ZipEntry.ExtractExistingFile"/> property on the
		/// corresponding ZipEntry instance.  By default, the action taken in this case is to
		/// throw an exception.
		/// </para>
		///
		/// <para>
		/// For information on the syntax of the selectionCriteria string,
		/// see <see cref="AddSelectedFiles(String)" />.
		/// </para>
		/// </remarks>
		///
		/// <example>
		/// This example shows how extract all XML files modified after 15 January 2009.
		/// <code>
		/// using (ZipFile zip = ZipFile.Read(zipArchiveName))
		/// {
		///   zip.ExtractSelectedEntries("name = *.xml  and  mtime &gt; 2009-01-15");
		/// }
		/// </code>
		/// </example>
		/// <param name="selectionCriteria">the selection criteria for entries to extract.</param>
		///
		/// <seealso cref="ExtractSelectedEntries(String,ExtractExistingFileAction)"/>
		public void ExtractSelectedEntries(String selectionCriteria)
		{
			foreach (ZipEntry e in SelectEntries(selectionCriteria))
			{
				e.Password = _Password; // possibly null
				e.Extract();
			}
		}


		/// <summary>
		/// Selects and Extracts a set of Entries from the ZipFile.
		/// </summary>
		///
		/// <remarks>
		/// <para>
		/// The entries are extracted into the current working directory. When extraction would would
		/// overwrite an existing filesystem file, the action taken is as specified in the
		/// <paramref name="extractExistingFile"/> parameter.
		/// </para>
		///
		/// <para>
		/// For information on the syntax of the string describing the entry selection criteria,
		/// see <see cref="AddSelectedFiles(String)" />.
		/// </para>
		/// </remarks>
		///
		/// <example>
		/// This example shows how extract all XML files modified after 15 January 2009,
		/// overwriting any existing files.
		/// <code>
		/// using (ZipFile zip = ZipFile.Read(zipArchiveName))
		/// {
		///   zip.ExtractSelectedEntries("name = *.xml  and  mtime &gt; 2009-01-15",
		///                              ExtractExistingFileAction.OverwriteSilently);
		/// }
		/// </code>
		/// </example>
		///
		/// <param name="selectionCriteria">the selection criteria for entries to extract.</param>
		///
		/// <param name="extractExistingFile">
		/// The action to take if extraction would overwrite an existing file.
		/// </param>
		public void ExtractSelectedEntries(String selectionCriteria, ExtractExistingFileAction extractExistingFile)
		{
			foreach (ZipEntry e in SelectEntries(selectionCriteria))
			{
				e.Password = _Password; // possibly null
				e.Extract(extractExistingFile);
			}
		}


		/// <summary>
		/// Selects and Extracts a set of Entries from the ZipFile.
		/// </summary>
		///
		/// <remarks>
		/// <para>
		/// The entries are selected from the specified directory within the archive, and then
		/// extracted into the current working directory.
		/// </para>
		///
		/// <para>
		/// If any of the files to be extracted already exist, then the action taken is as
		/// specified in the <see cref="ZipEntry.ExtractExistingFile"/> property on the
		/// corresponding ZipEntry instance.  By default, the action taken in this case is to
		/// throw an exception.
		/// </para>
		///
		/// <para>
		/// For information on the syntax of the string describing the entry selection criteria,
		/// see <see cref="AddSelectedFiles(String)" />.
		/// </para>
		/// </remarks>
		///
		/// <example>
		/// This example shows how extract all XML files modified after 15 January 2009,
		/// and writes them to the "unpack" directory.
		/// <code>
		/// using (ZipFile zip = ZipFile.Read(zipArchiveName))
		/// {
		///   zip.ExtractSelectedEntries("name = *.xml  and  mtime &gt; 2009-01-15","unpack");
		/// }
		/// </code>
		/// </example>
		///
		/// <param name="selectionCriteria">the selection criteria for entries to extract.</param>
		///
		/// <param name="directoryPathInArchive">
		/// the directory in the archive from which to select entries. If null, then
		/// all directories in the archive are used.
		/// </param>
		///
		/// <seealso cref="ExtractSelectedEntries(String,String,String,ExtractExistingFileAction)"/>
		public void ExtractSelectedEntries(String selectionCriteria, String directoryPathInArchive)
		{
			foreach (ZipEntry e in SelectEntries(selectionCriteria, directoryPathInArchive))
			{
				e.Password = _Password; // possibly null
				e.Extract();
			}
		}


		/// <summary>
		/// Selects and Extracts a set of Entries from the ZipFile.
		/// </summary>
		///
		/// <remarks>
		/// <para>
		/// The entries are extracted into the specified directory. If any of the files to be
		/// extracted already exist, an exception will be thrown.
		/// </para>
		/// <para>
		/// For information on the syntax of the string describing the entry selection criteria,
		/// see <see cref="AddSelectedFiles(String)" />.
		/// </para>
		/// </remarks>
		///
		/// <param name="selectionCriteria">the selection criteria for entries to extract.</param>
		///
		/// <param name="directoryInArchive">
		/// the directory in the archive from which to select entries. If null, then
		/// all directories in the archive are used.
		/// </param>
		///
		/// <param name="extractDirectory">
		/// the directory on the disk into which to extract. It will be created
		/// if it does not exist.
		/// </param>
		public void ExtractSelectedEntries(String selectionCriteria, string directoryInArchive, string extractDirectory)
		{
			foreach (ZipEntry e in SelectEntries(selectionCriteria, directoryInArchive))
			{
				e.Password = _Password; // possibly null
				e.Extract(extractDirectory);
			}
		}


		/// <summary>
		/// Selects and Extracts a set of Entries from the ZipFile.
		/// </summary>
		///
		/// <remarks>
		/// <para>
		/// The entries are extracted into the specified directory. When extraction would would
		/// overwrite an existing filesystem file, the action taken is as specified in the
		/// <paramref name="extractExistingFile"/> parameter.
		/// </para>
		///
		/// <para>
		/// For information on the syntax of the string describing the entry selection criteria,
		/// see <see cref="AddSelectedFiles(String)" />.
		/// </para>
		/// </remarks>
		///
		/// <example>
		/// This example shows how extract all files  with an XML extension or with  a size larger than 100,000 bytes,
		/// and puts them in the unpack directory.  For any files that already exist in
		/// that destination directory, they will not be overwritten.
		/// <code>
		/// using (ZipFile zip = ZipFile.Read(zipArchiveName))
		/// {
		///   zip.ExtractSelectedEntries("name = *.xml  or  size &gt; 100000",
		///                              null,
		///                              "unpack",
		///                              ExtractExistingFileAction.DontOverwrite);
		/// }
		/// </code>
		/// </example>
		///
		/// <param name="selectionCriteria">the selection criteria for entries to extract.</param>
		///
		/// <param name="extractDirectory">
		/// The directory on the disk into which to extract. It will be created if it does not exist.
		/// </param>
		///
		/// <param name="directoryPathInArchive">
		/// The directory in the archive from which to select entries. If null, then
		/// all directories in the archive are used.
		/// </param>
		///
		/// <param name="extractExistingFile">
		/// The action to take if extraction would overwrite an existing file.
		/// </param>
		///
		public void ExtractSelectedEntries(String selectionCriteria, string directoryPathInArchive, string extractDirectory, ExtractExistingFileAction extractExistingFile)
		{
			foreach (ZipEntry e in SelectEntries(selectionCriteria, directoryPathInArchive))
			{
				e.Password = _Password; // possibly null
				e.Extract(extractDirectory, extractExistingFile);
			}
		}

	}

	internal abstract partial class SelectionCriterion
	{
		internal abstract bool Evaluate(PickGold.Zip.ZipEntry entry);
	}


	internal partial class NameCriterion : SelectionCriterion
	{
		internal override bool Evaluate(PickGold.Zip.ZipEntry entry)
		{
			// swap forward slashes in the entry.FileName for backslashes
			string transformedFileName = entry.FileName.Replace("/", "\\");

			return _Evaluate(transformedFileName);
		}
	}


	internal partial class SizeCriterion : SelectionCriterion
	{
		internal override bool Evaluate(PickGold.Zip.ZipEntry entry)
		{
			return _Evaluate(entry.UncompressedSize);
		}
	}

	internal partial class TimeCriterion : SelectionCriterion
	{
		internal override bool Evaluate(PickGold.Zip.ZipEntry entry)
		{
			DateTime x;
			switch (Which)
			{
				case WhichTime.atime:
					x = entry.AccessedTime;
					break;
				case WhichTime.mtime:
					x = entry.ModifiedTime;
					break;
				case WhichTime.ctime:
					x = entry.CreationTime;
					break;
				default: throw new ArgumentException("??time");
			}
			return _Evaluate(x);
		}
	}


	internal partial class TypeCriterion : SelectionCriterion
	{
		internal override bool Evaluate(PickGold.Zip.ZipEntry entry)
		{
			bool result = (ObjectType == 'D')
				? entry.IsDirectory
				: !entry.IsDirectory;

			if (Operator != ComparisonOperator.EqualTo)
				result = !result;
			return result;
		}
	}

#if !SILVERLIGHT
	internal partial class AttributesCriterion : SelectionCriterion
	{
		internal override bool Evaluate(PickGold.Zip.ZipEntry entry)
		{
			FileAttributes fileAttrs = entry.Attributes;
			return _Evaluate(fileAttrs);
		}
	}
#endif

	internal partial class CompoundCriterion : SelectionCriterion
	{
		internal override bool Evaluate(PickGold.Zip.ZipEntry entry)
		{
			bool result = Left.Evaluate(entry);
			switch (Conjunction)
			{
				case LogicalConjunction.AND:
					if (result)
						result = Right.Evaluate(entry);
					break;
				case LogicalConjunction.OR:
					if (!result)
						result = Right.Evaluate(entry);
					break;
				case LogicalConjunction.XOR:
					result ^= Right.Evaluate(entry);
					break;
			}
			return result;
		}
	}



	public partial class FileSelector
	{
		private bool Evaluate(PickGold.Zip.ZipEntry entry)
		{
			bool result = _Criterion.Evaluate(entry);
			return result;
		}

		/// <summary>
		/// Retrieve the ZipEntry items in the ZipFile that conform to the specified criteria.
		/// </summary>
		/// <remarks>
		///
		/// <para>
		/// This method applies the criteria set in the FileSelector instance (as described in
		/// the <see cref="FileSelector.SelectionCriteria"/>) to the specified ZipFile.  Using this
		/// method, for example, you can retrieve all entries from the given ZipFile that
		/// have filenames ending in .txt.
		/// </para>
		///
		/// <para>
		/// Normally, applications would not call this method directly.  This method is used
		/// by the ZipFile class.
		/// </para>
		///
		/// <para>
		/// Using the appropriate SelectionCriteria, you can retrieve entries based on size,
		/// time, and attributes. See <see cref="FileSelector.SelectionCriteria"/> for a
		/// description of the syntax of the SelectionCriteria string.
		/// </para>
		///
		/// </remarks>
		///
		/// <param name="zip">The ZipFile from which to retrieve entries.</param>
		///
		/// <returns>a collection of ZipEntry objects that conform to the criteria.</returns>
		public ICollection<PickGold.Zip.ZipEntry> SelectEntries(PickGold.Zip.ZipFile zip)
		{
			if (zip == null)
				throw new ArgumentNullException("zip");

			var list = new List<PickGold.Zip.ZipEntry>();

			foreach (PickGold.Zip.ZipEntry e in zip)
			{
				if (this.Evaluate(e))
					list.Add(e);
			}

			return list;
		}


		/// <summary>
		/// Retrieve the ZipEntry items in the ZipFile that conform to the specified criteria.
		/// </summary>
		/// <remarks>
		///
		/// <para>
		/// This method applies the criteria set in the FileSelector instance (as described in
		/// the <see cref="FileSelector.SelectionCriteria"/>) to the specified ZipFile.  Using this
		/// method, for example, you can retrieve all entries from the given ZipFile that
		/// have filenames ending in .txt.
		/// </para>
		///
		/// <para>
		/// Normally, applications would not call this method directly.  This method is used
		/// by the ZipFile class.
		/// </para>
		///
		/// <para>
		/// This overload allows the selection of ZipEntry instances from the ZipFile to be restricted
		/// to entries contained within a particular directory in the ZipFile.
		/// </para>
		///
		/// <para>
		/// Using the appropriate SelectionCriteria, you can retrieve entries based on size,
		/// time, and attributes. See <see cref="FileSelector.SelectionCriteria"/> for a
		/// description of the syntax of the SelectionCriteria string.
		/// </para>
		///
		/// </remarks>
		///
		/// <param name="zip">The ZipFile from which to retrieve entries.</param>
		///
		/// <param name="directoryPathInArchive">
		/// the directory in the archive from which to select entries. If null, then
		/// all directories in the archive are used.
		/// </param>
		///
		/// <returns>a collection of ZipEntry objects that conform to the criteria.</returns>
		public ICollection<PickGold.Zip.ZipEntry> SelectEntries(PickGold.Zip.ZipFile zip, string directoryPathInArchive)
		{
			if (zip == null)
				throw new ArgumentNullException("zip");

			var list = new List<PickGold.Zip.ZipEntry>();
			// workitem 8559
			string slashSwapped = (directoryPathInArchive == null) ? null : directoryPathInArchive.Replace("/", "\\");
			// workitem 9174
			if (slashSwapped != null)
			{
				while (slashSwapped.EndsWith("\\"))
					slashSwapped = slashSwapped.Substring(0, slashSwapped.Length - 1);
			}
			foreach (PickGold.Zip.ZipEntry e in zip)
			{
				if (directoryPathInArchive == null || (Path.GetDirectoryName(e.FileName) == directoryPathInArchive)
					|| (Path.GetDirectoryName(e.FileName) == slashSwapped)) // workitem 8559
					if (this.Evaluate(e))
						list.Add(e);
			}

			return list;
		}

	}
}
